What does the Friedmann equation tell us?

What does the Friedmann equation tell us?

The Friedmann equation which models the expanding universe has a parameter k called the curvature parameter which is indicative of the rate of expansion and whether or not that expansion rate is increasing or decreasing. It indicates the future fate of the universe.

What did Friedmann discover?

Ninety years ago, Russian physicist Alexander Friedmann (1888–1925) demonstrated for the first time that Albert Einstein’s general theory of relativity (GR) admits nonstatic solutions. It can, he found, describe a cosmos that expands, contracts, collapses, and might even have been born in a singularity.

What is the oscillating theory of the universe?

A modification of the Big Bang theory, in which an expanding universe eventually reverses and collapses back to a Big Crunch before starting to expand again, forming one cycle of an endless series. In such a model, each cycle has a finite duration but the universe itself can last for an infinite time.

Who made the oscillating universe theory?

Einstein first proposed this theory in the 1920’s in response to the model of the expanding universe.

What is the Friedmann universe theory?

Friedmann universe, model universe developed in 1922 by the Russian meteorologist and mathematician Aleksandr Friedmann (1888–1925). He believed that Albert Einstein’s general theory of relativity required a theory of the universe in motion, as opposed to the static universe that scientists until then had proposed.

How is the Friedmann equation used to determine the age of the universe?

The Friedmann equation includes the Hubble constant to give a much more accurate age of the universe. In this equation, G is the gravitational constant = 6.67*10-11Nm2/kg2, ρr is the radiation density of the universe, ρm is the matter density of the universe, and ρd is the dark energy density of the universe.

What was the Friedmann universe theory?

What is Friedmann model?

noun Astronomy. any model of the universe deduced from a homogeneous, isotropic solution of Einstein’s field equations without a cosmological constant. Such models form the mathematical basis for many modern cosmologies and provide for expansion or contraction of the universe. Also called Friedmann universe.

How was the oscillating universe theory created?

For example, the oscillating universe theory briefly considered by Albert Einstein in 1930 theorized a universe following an eternal series of oscillations, each beginning with a Big Bang and ending with a Big Crunch; in the interim, the universe would expand for a period of time before the gravitational attraction of …

What does oscillating theory mean?

The Oscillating Universe Theory is a cosmological model that combines both the Big Bang and the Big Crunch as part of a cyclical event. That is, if this theory holds true, then the Universe in which we live in exists between a Big Bang and a Big Crunch.

When was the 1st proposition of the pulsating theory?

variable stars The pulsation theory was first proposed as a possible explanation as early as 1879, was applied to Cepheids in 1914, and was further developed by Arthur Eddington in 1917–18.

How is the Friedmann equation derived?

A proper derivation of the Friedmann equation begins by inserting the Friedmann-Robertson- Walker metric into the Einstein Field Equation. Since GR yields the Newtonian limit, we should expect the small scale behavior to resemble that of our Newtonian derivation above, and it does, with two important changes.